Russian physicist Anatoly Maslov was convicted of treason on Tuesday and sentenced to 14 years in a penal colony, a Reuters reporter at the court said.

Maslov, 77, is one of a string of eminent Russian scientists who have been charged with treason in recent years.

He and a number of the others had conducted theoretical work in areas relevant to the development of hypersonic missiles - cutting-edge weapons capable of carrying payloads at up to 10 times the speed of sound to punch through air-defence systems.

Maslov was convicted by a St Petersburg court following a trial that was close to the media. He had protested his innocence.